[workloadmeta] Add ContainerImageMetadata Kind

pkg/tagger/collectors/workloadmeta_extract.go

@@ -133,6 +133,8 @@ func (c *WorkloadMetaCollector) processEvents(evBundle workloadmeta.EventBundle)
 				tagInfos = append(tagInfos, c.handleKubePod(ev)...)
 			case workloadmeta.KindECSTask:
 				tagInfos = append(tagInfos, c.handleECSTask(ev)...)
+			case workloadmeta.KindContainerImageMetadata:
+				// No tags for now
 			default:
 				log.Errorf("cannot handle event for entity %q with kind %q", entityID.ID, entityID.Kind)
 			}
@@ -594,6 +596,8 @@ func buildTaggerEntityID(entityID workloadmeta.EntityID) string {
 		return kubelet.PodUIDToTaggerEntityName(entityID.ID)
 	case workloadmeta.KindECSTask:
 		return fmt.Sprintf("ecs_task://%s", entityID.ID)
+	case workloadmeta.KindContainerImageMetadata:
+		return fmt.Sprintf("container_image_metadata://%s", entityID.ID)
 	default:
 		log.Errorf("can't recognize entity %q with kind %q; trying %s://%s as tagger entity",
 			entityID.ID, entityID.Kind, entityID.ID, entityID.Kind)

pkg/workloadmeta/dump.go

@@ -55,6 +55,8 @@ func (s *store) Dump(verbose bool) WorkloadDumpResponse {
 			info = e.String(verbose)
 		case *ECSTask:
 			info = e.String(verbose)
+		case *ContainerImageMetadata:
+			info = e.String(verbose)
 		default:
 			return "", fmt.Errorf("unsupported type %T", e)
 		}

pkg/workloadmeta/store.go

@@ -311,6 +311,19 @@ func (s *store) GetECSTask(id string) (*ECSTask, error) {
 	return entity.(*ECSTask), nil
 }
 
+// ListImages implements Store#ListImages
+func (s *store) ListImages() []*ContainerImageMetadata {
+	entities := s.listEntitiesByKind(KindContainerImageMetadata)
+
+	images := make([]*ContainerImageMetadata, 0, len(entities))
+	for _, entity := range entities {
+		image := entity.(*ContainerImageMetadata)
+		images = append(images, image)
+	}
+
+	return images
+}
+
 // Notify implements Store#Notify
 func (s *store) Notify(events []CollectorEvent) {
 	if len(events) > 0 {

pkg/workloadmeta/store_test.go

@@ -683,6 +683,47 @@ func TestListContainersWithFilter(t *testing.T) {
 	assert.DeepEqual(t, []*Container{runningContainer}, runningContainers)
 }
 
+func TestListImages(t *testing.T) {
+	image := &ContainerImageMetadata{
+		EntityID: EntityID{
+			Kind: KindContainerImageMetadata,
+			ID:   "abc",
+		},
+	}
+
+	tests := []struct {
+		name           string
+		preEvents      []CollectorEvent
+		expectedImages []*ContainerImageMetadata
+	}{
+		{
+			name: "some images stored",
+			preEvents: []CollectorEvent{
+				{
+					Type:   EventTypeSet,
+					Source: fooSource,
+					Entity: image,
+				},
+			},
+			expectedImages: []*ContainerImageMetadata{image},
+		},
+		{
+			name:           "no containers stored",
+			preEvents:      nil,
+			expectedImages: []*ContainerImageMetadata{},
+		},
+	}
+
+	for _, test := range tests {
+		t.Run(test.name, func(t *testing.T) {
+			testStore := newTestStore()
+			testStore.handleEvents(test.preEvents)
+
+			assert.DeepEqual(t, test.expectedImages, testStore.ListImages())
+		})
+	}
+}
+
 func newTestStore() *store {
 	return &store{
 		store: make(map[Kind]map[string]*cachedEntity),

pkg/workloadmeta/testing/store.go

@@ -104,6 +104,19 @@ func (s *Store) GetECSTask(id string) (*workloadmeta.ECSTask, error) {
 	return entity.(*workloadmeta.ECSTask), nil
 }
 
+// ListImages implements Store#ListImages
+func (s *Store) ListImages() []*workloadmeta.ContainerImageMetadata {
+	entities := s.listEntitiesByKind(workloadmeta.KindContainerImageMetadata)
+
+	images := make([]*workloadmeta.ContainerImageMetadata, 0, len(entities))
+	for _, entity := range entities {
+		image := entity.(*workloadmeta.ContainerImageMetadata)
+		images = append(images, image)
+	}
+
+	return images
+}
+
 // Set sets an entity in the store.
 func (s *Store) Set(entity workloadmeta.Entity) {
 	s.mu.Lock()

pkg/workloadmeta/types.go

@@ -12,6 +12,7 @@ import (
 	"time"
 
 	"github.com/mohae/deepcopy"
+	"github.com/opencontainers/image-spec/specs-go/v1"
 
 	"github.com/DataDog/datadog-agent/pkg/util/containers"
 )
@@ -73,6 +74,10 @@ type Store interface {
 	// kind KindECSTask and the given ID.
 	GetECSTask(id string) (*ECSTask, error)
 
+	// ListImages returns metadata about all known images, equivalent to all
+	// entities with kind KindContainerImageMetadata.
+	ListImages() []*ContainerImageMetadata
+
 	// Notify notifies the store with a slice of events.  It should only be
 	// used by workloadmeta collectors.
 	Notify(events []CollectorEvent)
@@ -86,9 +91,10 @@ type Kind string
 
 // Defined Kinds
 const (
-	KindContainer     Kind = "container"
-	KindKubernetesPod Kind = "kubernetes_pod"
-	KindECSTask       Kind = "ecs_task"
+	KindContainer              Kind = "container"
+	KindKubernetesPod          Kind = "kubernetes_pod"
+	KindECSTask                Kind = "ecs_task"
+	KindContainerImageMetadata Kind = "container_image_metadata"
 )
 
 // Source is the source name of an entity.
@@ -596,6 +602,102 @@ func (t ECSTask) String(verbose bool) string {
 
 var _ Entity = &ECSTask{}
 
+// ContainerImageMetadata is an Entity that represents container image metadata
+type ContainerImageMetadata struct {
+	EntityID
+	EntityMeta
+	ShortName    string
+	RepoTags     []string
+	RepoDigests  []string
+	MediaType    string
+	SizeBytes    int64
+	OS           string
+	OSVersion    string
+	Architecture string
+	Variant      string
+	Layers       []ContainerImageLayer
+}
+
+// ContainerImageLayer represents a layer of a container image
+type ContainerImageLayer struct {
+	MediaType string
+	Digest    string
+	SizeBytes int64
+	URLs      []string
+	History   v1.History
+}
+
+// GetID implements Entity#GetID.
+func (i ContainerImageMetadata) GetID() EntityID {
+	return i.EntityID
+}
+
+// Merge implements Entity#Merge.
+func (i *ContainerImageMetadata) Merge(e Entity) error {
+	otherImage, ok := e.(*ContainerImageMetadata)
+	if !ok {
+		return fmt.Errorf("cannot merge ContainerImageMetadata with different kind %T", e)
+	}
+
+	return merge(i, otherImage)
+}
+
+// DeepCopy implements Entity#DeepCopy.
+func (i ContainerImageMetadata) DeepCopy() Entity {
+	cp := deepcopy.Copy(i).(ContainerImageMetadata)
+	return &cp
+}
+
+// String implements Entity#String.
+func (i ContainerImageMetadata) String(verbose bool) string {
+	var sb strings.Builder
+
+	_, _ = fmt.Fprintln(&sb, "----------- Entity ID -----------")
+	_, _ = fmt.Fprint(&sb, i.EntityID.String(verbose))
+
+	_, _ = fmt.Fprintln(&sb, "----------- Entity Meta -----------")
+	_, _ = fmt.Fprint(&sb, i.EntityMeta.String(verbose))
+
+	_, _ = fmt.Fprintln(&sb, "Short name:", i.ShortName)
+	_, _ = fmt.Fprintln(&sb, "Repo tags:", i.RepoTags)
+	_, _ = fmt.Fprintln(&sb, "Repo digests:", i.RepoDigests)
+
+	if verbose {
+		_, _ = fmt.Fprintln(&sb, "Media Type:", i.MediaType)
+		_, _ = fmt.Fprintln(&sb, "Size in bytes:", i.SizeBytes)
+		_, _ = fmt.Fprintln(&sb, "OS:", i.OS)
+		_, _ = fmt.Fprintln(&sb, "OS Version:", i.OSVersion)
+		_, _ = fmt.Fprintln(&sb, "Architecture:", i.Architecture)
+		_, _ = fmt.Fprintln(&sb, "Variant:", i.Variant)
+
+		_, _ = fmt.Fprintln(&sb, "----------- Layers -----------")
+		for _, layer := range i.Layers {
+			if layer.SizeBytes != 0 { // Skip layers that have a history command associated but are empty
+				_, _ = fmt.Fprintln(&sb, layer)
+			}
+		}
+	}
+
+	return sb.String()
+}
+
+// String returns a string representation of ContainerImageLayer
+func (layer ContainerImageLayer) String() string {
+	var sb strings.Builder
+
+	_, _ = fmt.Fprintln(&sb, "Media Type:", layer.MediaType)
+	_, _ = fmt.Fprintln(&sb, "Digest:", layer.Digest)
+	_, _ = fmt.Fprintln(&sb, "Size in bytes:", layer.SizeBytes)
+	_, _ = fmt.Fprintln(&sb, "URLs:", layer.URLs)
+
+	// layer.History is not included here because it's way too verbose (includes
+	// the command in the Dockerfile that generated the layer).
+
+	return sb.String()
+}
+
+var _ Entity = &ContainerImageMetadata{}
+
 // CollectorEvent is an event generated by a metadata collector, to be handled
 // by the metadata store.
 type CollectorEvent struct {